Modulating the polarization-resolved second harmonic generation response of a Sulfamic acid multicomponent crystal via amino acid coformer selection

<jats:p>Materials with a non-centrosymmetric crystal lattice find applications in areas ranging from laser technology to optoelectronics. While inorganic materials remain the benchmark, semi-organic multicomponent crystals (MCCs) have potential as sustainable and customizable alternatives, due to their simple synthesis procedures, low cost and the possibility of structure-property control. Sulfamic acid (Sa) is a versatile base whose properties can be altered depending on the co-former used. Herein, five MCCs of Sa with different amino acids, L-Arginine (Sa•L-Arg•0.5H2O; 1), Glycine (Sa•Gly; 2), L-Histidine (Sa•L-Hist; 3), L-Methionine (Sa•L-Met; 4), and L-Phenylalanine (Sa•L-PhAla; 5) have been synthesized, systematically characterized and grown in millimeter scale polycrystalline discs. Polarization-resolved second harmonic generation microscopy revealed markedly different polarization profiles and degrees of crystallisation. Compared to potassium dihydrate phosphide (KDP), the relative effective second order nonlinear susceptibilities of MCCs 1 (0.9 ± 0.5) and 2 (0.35 ± 0.2) are lower while MCCs 3 (3 ± 1.5), 4 (3.9 ± 1.9), and 5 (2 ± 1) are more efficient. These results demonstrate the potential of both amino acids as coformers and sulfamic acid as a modifiable parent material to be used as active, polarisation-dependent second harmonic generation materials.</jats:p>